I have been running a bunch of $8 Koolance 120x38 116CFM fans with a fan controller. The fans are about 9 months old. I am running them horizontal. They actually make more noise in vertical. Do most dual ball bearing 120x38mm fans have this vibration? Is it worth running San Ace 120x38mm ball bearing fans or will they make similar noise. Are single ball bearing fans quieter? Do you guys have any recommended 120x38 models? Edit: I doubled up some rubber fan isolators and it took care of about half the harmonics, I think the large motor is flexing the metal of my case and making it sing, still curious about higher end 120x38mm thick fans though. A lot of the used server fans are brushless, will these brushless fans still fail with horizontal operation?